package com.lgc.demo.collection;

import java.util.HashSet;
import java.util.Set;
import java.util.TreeSet;


public class HashSetTest {
    public static void main(String[] args) {
        Set set = new HashSet();
        set.add("aa");
        set.add("bb");
        set.add("aa");

        int size = set.size();


        int a=0;
    }


}
